Purpose This study aims to investigate the influence of online opinion leadership and opinion seeking the intention to purchase and purchase behaviour of organic food in Saudi Arabia. Design/methodology/approach This study used an online questionnaire as a method to collect data from Instagram users in Saudi Arabia. Statistical analysis was performed using the SmartPLS to test the research model. Findings The study demonstrates the links between the perceived benevolence of the opinion leadership through Instagram and purchase behaviour of organic food and between opinion seeking and intention to purchase. Practical implications This study provides insights into the favourable impact of opinion leadership and opinion seeking on consumers’ intention to purchase and purchase behaviour for marketers, especially in the organic food sector of a Middle Eastern context. Originality/value Prior studies have investigated the impact of opinion leadership and opinion seeking on purchase behaviour, but not within the organic food sector. This study attempts to fill this gap in the literature by providing useful insights to enhance the understanding of the influence of online opinion leadership on purchase behaviour of organic food. This study also makes a valuable contribution to organic food research in Middle East countries, where there is a lack of research on organic food purchase behaviour.